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(No Mddel.) Y 2 Sheets-Sheet 1.

G.A.-BARTH. I DIRECT ACTING STEAM OR PNEUMATIC ENGINE.

N0..397,958. Patented Feb! 19, 1889.

(No Model.) 2 Sheets-Sheet 2 G. A. EARTH. DIREGT ACTING- STEAM 0R PNEUMATIC ENGINE.

No. 397,958. Patented Feb. 19, 1889.

fvmwroza N. PETERS. Phnlu-Ll'hagmpher. Wnshmglon. D4 Cv NITED STATES PATENT OFFICE.

GUSTAV A. EARTH, OF ."I. LOUIS, MISSOURI, ASSIGNOR TO PIERRE CIIOU- TEAU, OF SAME PLACE.

DIRECT=ACTING STEAM OR PNEUMATIC ENGINE.

SPECIFICATION forming part of Letters Patent No. 397,958, dated February 19, 1889.

Application filed A t 27, 1888. Serial No. 283,895. (No model.)

To [LZZ whom it may concern.-

Be it known that I, GUSTAV A. EARTH, a citizen of the United States, residing in the city of St. Louis, State of Missouri, have invented certain new and useful Improvements in Direct-Acting Steam or Pneumatic Engines, of which the following is a full, clear, and exact description.

My invention relates to improvements in direct -acting steam or pneumatic engines wherein the piston is reciprocated in the cylinder by its valve without the intervention of valve-operating mechanism, and has for its object to obtain a uniform pressure on both sides of the piston and to simplify the arrangement of the inlet and outlet passages in the piston and valve. I

My invention comprises a cylinder provided with an inlet and exhaust port; a piston fitted therein, having an internal chamber and provided with a separate inlet and exhaust space or pocket corresponding to the inlet and exhaust port, respectively, of the cylinder, and communicating by ports, respectively, with the piston chamber; two separate combined inlet and exhaust passages between the piston-chamber and cylinder on each side of the piston, respectively; a distribution valve within said chamber, and a separate inlet and outlet relief-passage between each end of the chamber and the outside of the piston, the whole operating to hold and reverse the distribution-valve at the proper times, and thereby govern the admission and exhaust of the steam or other motive-fluid to and from each side of the piston alternately.

On the accompanying drawings, Figure 1 represents a central longitudinal section of my improved direct-acting engine, the piston being shown at the front end of its stroke in the cylinder and Figs. 2 and 3, transverse sections thereof on lines 1 1 and 2 2, respectively, in Fig. 1; Fig. l, a similar view to Fig. 1, with the pistonwithin a short distance of the opposite end of its stroke; and Fig. 5, a transverse section thereof on line 3 3.

Like letters of reference denote like parts in all the figures.

a represents the cylinder, having an inletport, b,'and an exhaust-port, 0, located opposite to each other midway along the cylinder a.

(Z is the piston, which is formed with a central longitudinal chamber, e, closed at each end.

fis an inlet and g an outlet space or pocket formed opposite to each other in the circumference of the piston d, in line, respectively, with the inlet and outlet ports I) and c of the cylinder a. From the inlet-space f is a central port, f, and from the outlet-space g two end-ports, g g comnuinicating, respectively, with the chamber 6, from which, at an equal distance to the front and rear of and in line with the opening of port f, are two separate combined inlet and outlet passages, h 72 extending longitudinally through the wall of the piston (Z in opposite directions, so that the passage 71/ communicates with the cylinder a on the front side of the piston (Z and the passage 71 on the opposite side of the piston d. Vithin the chamber 6 is fitted a distributionvalve, '2', preferably circular in form, having three circumferential grooves or passages,' j j j extending entirely around the valve 1', the passage j commanding the inlet port and passage f h and f 712 alternately, passage j commanding the outlet passage and port h g,and the passage j commanding the outlet passage an d port 7L2 g during the operation of the valve 1', as hereinafter more particularly referred to. Near the front end of the piston (l, in line with the inlet-port Z) of the cylinder a, is an inlet relief-passage, k, opening from the outside of the piston (Z into the corresponding end of the chamber 6, from which end an outlet relief-passage, I, (see Fig. 1,) extends longitudinally through the wall of the piston d to the outside of the latter near its rear end. A similar inlet relief-passage, k, and outlet relief-passage, Z, (see Fig. 2,) open from the rear end of the chamber 6 to the outside of the piston cl.

As seen in Fig. l, the piston d is at the front end of its stroke in the cylinder a and the distrilmtion-valve at the corresponding end of the chamber 6, so that its passages j j establish communication between the inlet-port f and passage h and between the outlet-pas sage 71 and port 9 communicating with the outlet-space g, in which position steam enter= ing through the inlet-port 7) of the cylinder at passes through the inlet relief-passage 71:, as indicated by the arrows, into the chamber 6, for supporting the distribution-valvc i during the return-stroke of the piston (I. At the same timesteam enters the inletspaee fand passes through portf and passagej into and through passage 7L into the cylinder (1 on the front side of the piston d, which is thereby forced along the cylinder (t until near the rear end of its stroke, (see Fig. 2,) when, the outlet relief-passage l from the rear end of the cham ber 8 opening to the exhaust-port c, and the inlet reliefipassage It at the front end of the chamber 6 opening to the inlet-port Zr, the steam which was in the chamber 9 behind the valve '1? is exhausted, and at the same time steam is admitted to the front end of the chamber c, which throws the distributionvalve 1 to the rear end of the chamber 6, and thereby changes the position of its passagesj j, so as to open communication between the inlet-port f and passage 72?, and between the outlet-passage 71 and port g, which causes the steam to enter from the space f through port f and passage 71 to the rear side of the piston d, and the steam previously on the front side of the piston d to be exhausted through passage 71 and port g into the outlet-space g, when the piston (Z is forced forward toward its original position, (seen in Fig. 1,) on approaching which the outlet relief-passage Z from the front end of the chamber 6 opens to the exhaust-port c, and the inlet relief-passage k' at the rear end of the chambereopens to the inlet-port b and throws the distributionwalve 1 forward for moving its passagesj 7' so as to open communication, as before,be-

tween inlet-port f and passage 7L, and between outlet-passage 71 and port g for reversing the motion of the piston d, and so on to and fro in the cylinder a. i

I claim The combination of a cylinder, at, having inlet and exhaust ports I) c, a piston, d,having an internal chamber, c, and inlet and outlet spaces or pockets f g, communicating-portsf and g 9 between the respective spaces fg and chamber 6, combined inlet and outlet passages 71 7L2 in piston d between chamber 6 and cylinder a, inlet relief-passages 7a 7.0, and outlet relief-passages Z Z in piston (Z, opening into each end of the chamber 0 and on the outside of piston (Z, with the distributiona'alx'e1 ,hav-

ing circumferential depressions or pau :agesj ff, substantially as shown, and for the purpose described.

In testimony whereof I have affixed mysignature, in presence of two witnesses, this 21st day of August, 1888.

GUSTAV A. EARTH.

\V itnesses:

PAUL BAKEVVELL, WILLIAM BYRNE. 

